Method of making cartridge cases



y 9 J. F. BABBITT 2,349,840

METHOD OF MAKING CARTRIDGE GASES Filed July 9, 1942 2 Sheets-Sheet l I I m I I I grwqmm akn 2302323? y J. F. BABBITT 2,349,840

METHOD OF MAKING CARTRTDGE CASES Filed July 9, 1942 2 Sheets-Sheet 2 M RR JMMMM w /aZZ attain;

Patented May 30, 1944 .ZUNITED STAT METHOD or MAKING CARTRIDGE CASES John F. Babbitt, Louisville; Ky., 'assignor to J. v.

Pilcher Mfg. 00., Louisville, Ky., a corporation of Kentucky Application July 9, 1942, Serial No. 450312 (Cl. 29-13) f 6 Claims.

This invention relates to a method of making a cartridge case, and more particularly concerns a cartridge case having a two-part construction.

Cartridge cases have commonly been constructed of a copper composition, and because such a substance may be readily worked, the cartridge case has been conveniently formed largely by a drawing operation. It is not readily possible, however, to make a cartridge case by this same procedure if the material employed is steel, for the reason that steel may not be readily Worked into a final desired shape by a drawing operation.

With the present invention a cartridge case may be constructed of steel and this is made possible by making the ease up asan assembly of two elements.

In the accompanying drawings, illustrating a preferred embodiment of the invention:

Fig. 1 is aside elevation of the two elements of the cartridge case prior to their assembly.

' Fig. 2 shows an initial step in the assembly of the elements to construct a cartridge case, the parts being in section.

Fig. 3 shows a succeeding step in the construction of the cartridge case, the parts being in section. 3

Fig, 4 is a longitudinal section through the resulting assembly of the two initial elements.

Fig. 5 is a section on the line 5-5 of Fig. 4.

* Fig. 6 is an enlarged section at the joint between the two assembled elements.

The elements from which is made the cartridge case of the invention include a cylindrical sleeve 1 which forms the side wall of the case, and a base plug 8 which partly enters and closes an end of the cylindrical sleeve. These two elements are separately fabricated as shown in Fig. 1, prior to their assembly. The cylindrical sleeve 1 may be merelya cut ofi portion of a seamless steel tube. Its one end should first be beveled on the exterior as shown at 9, and it has been found preferable that the angle a: be on the order of 55.

The base plug 8 may be readily fabricated from steel by turning it out from bar stock by a lathe'operation. This involves the reduction of one end portion N) to a smaller diameter so that it will tightly fit within the bore of the cylindrical sleeve 7. Both this smaller diameter portion and the larger diameter portion II should be of cylindrical formation. The larger diameter portion II should be of the same diameter as the outside of the sleeve 1.

At the junction of the larger and smaller diameter portions a groove is formed in the base plug 8. The side wall 12 of this groove which is adjacent the smaller diameter portion Ill, lies in a plane which is perpendicular to the axis of the base plug 8. The side wall l3 of the groove which is adjacent the larger diameter portion of the base plug should preferably be substantially at right angles to the axis of the base plug so that itwill present a shoulder against which the beveled end of: the cylindrical sleeve 1 will abut in the assembly operation. The bottom wall M of the groove should be curved so that it merges gradually into the side wall 13, but it may meet sharply with the other side wall 12.

In assembling these two elements the beveled end 9 of the cylindrical sleeve I is passed over the reducd portion ID of the base plug 8 until the beveled end 9 strikes the side wall of the groove. The cylindrical sleeve 1 is then-urged in the direction of the arrow withsuch force against the end wall l3 that the beveled end 9 is upset and enlarged as shown in Fig. 2. Any suitable press or other means may be employed to force the sleeve I axially, the base plug 8 being necessarily backed up during this pressing operation.

, In this upsetting operation it-is desirable that the cylindrical sleeve 1 be located within the bore of aforming block [6 so that the cylindrical sleeve will not become deformed under the endwise force which is applied to it. The bore through the forming block I6 is enlarged at I! at the portion thereof which lies outwardly from the enlarged part I I of the base plug 8. A curved formation I8 connects the largebore I1 with t e small bore through the block l6 and this curved formation is outwardly from the groove in the base plug 8 during the upsetting. action.

The upsetting of the beveled end 9 of the cylindrical sleeve 1 causes this end to turn inwardly and form an internal flange [9a, which partly fills the groove of the base plug 8, and also causes an outward bulging action so that an exterior peripheral ridge 2!] is formed upon the cylindrical shell. The enlarged bore ll of the forming block permits the outward bulge of the material to form this exterior ridge 20. The curved formation of the bottom wall M of the groove and the beveling of theend of the sleeve at 9 facilitates the inturning .01 the beveled end of the cylindrical sleeve 1 to form the flange l9a.

In the succeeding operation the base plug 8 is forced in the direction of the arrow into the interior of the forming block Hi to the position shown in Fig. 3. During this action the moveagainst the side -walli l 2 of the. groove. vThe resulting flange [9b therefore fills the groove in the base plug 8 side wall 12.

Inasmuch as the best results are. obtained if;

the final flange l9b fills the groove in. the base plug 8, this result may be achieved by upsetT ting the beveled end 9 to such an extent'thatf the combined volume of theridge 20 and flange l9a is substantially equal to the volume ofthe final flange l9b. This may be accomplished in,

practice because ithas been found that in the upsetting action the. flange [9a. is first formed andithereafterlthe. sleeve bulges outwardly .to formithe ridge 2.0.. Theupsettingforce is therefore. applied until this outward bulge results in abridge. 20 of. the size necessary to. causethe groove. in. the. base plug 8 to be filled when the ridgejils. is ..subsequently urged radially inwardly.

Thet 'assembled cartridge case which results from. thisxprocedure. may not bereadily separated because thelinternal flange 1912 which is sowformed. extends perpendicularly withinzthe cylindrical sleeveJ: and. engages in flat contact against. the endwall. l 2ofthegrooVe in the base plug 8. -.'I'he..sleeve..1;is.therefore in effect hooked into-.thesbaselplugj, bythe flange I91). To'separate the. twoiparts itwill. consequently be necessary-itonshear off this. internal flange I91) and inasmuchias the shearing strength of steel is considerable,..a strong interlocking connection is established.

Although for. purpose of explanation, theside wall I21 ofithe groove has been shownand described: as .lyingin aplane perpendicular to the and seats flat against thev directed force to'upset, said end oi the sleeve and form aninternal flange. entering said groove, and applying a radially inwardly directed force to carry said internal flange deeply into said grooveand against a sid Wall of the groove.

2. The method of making a metallic cartridg case which comprises upsetting an end of a cylindrical sleeve adjacent a peripheral groove in a a baseplug to an :extent toform-an internal flange partly filling said groove and to form an external peripheral ridge outside of said internal flange, and applying pressure to said ridge to force said flange deeply intosaid groove.

3. The method of making a metallic cartridge case comprising forcing one end of a cylindrical "sleeve over a reduced diameter portion of a base plug and against a shoulder presented by the larger diameter portion of the base plug until said end of the cylindrical sleeve is upset by said shoulder and forms an internal flange partially entering a peripheralgroove the base plugv at saidshoulder and also forms a, ridge around the exterior of the cylindrical sleeve portion outwardly: from said groove, and then. applying a force directed radiallyinwardlyof'the cylindrical sleeve upon said exterior ridge to turn the internal flange; against the side wall of the groove whichis adjacent the; reduced diameter portion ofthe base plug g 4. The method of making a metallic cartridge casewhich comprises beveling an end of a cylindrical sleeve, forcing said beveled end axially against a shoulder of a base plug to turn said end inwardly, into. a. peripheral groove of the base portion, said force being,- applieduntil the beveled end ofthe cylindrical sleeve portion partaxis-of; theba-sez'plug 8, this .side.. wall l2- may be. inclinedsoe, that it. is undercut. 'With such an undercutting of side wall I2, the flange. 19b will; be'turnedcinwardly more than 90 degrees toebeefiat;againstthewall l2. With such agconstruction, the: sleeve. 1 will. be. more. securely h'ookedftot-he.baseplugii. g

As a iurther feature of the invention-to pre-- vent. separation. of the two elements of the cartridge case, a: channeLZl may be formed inthe periphery of. the reduced portion-10 of the..base plug-,8. A brazing wire.22:wi11xbe located inthis channelZ-J before. thecylindrical sleeveis passed thereover. l. qAfterthe assembly of'sthe. two elements has.:-been= completed, sufilcient heat is-applied tothelcartridge case to meltthissbrazing wire and cause it.-.to.flow. outwardlybetween the meetingifacesn Thetwoelements will thereby be brazed together to vfurther resist their separation.

The succeeding steps which are performed upon thelcartridgetcaserwill.be the usual onesto give it.the..desired. form and to prepare; it for. the

.proiectile-and .firing means.

I claim: 7

l; The method of making a metallic cartridge casewhich comprises positioning an end or a cylindrical sleeve in registration with a peripheral groove of a base. plug, applying an axially 1y fills the groove and also until a peripheral ridge is formedexteriorly-of the cylindrical sleeve, and themapplying to saidexterio ridge-a force directed; radially inwardly of the; cylindricalsleeve t turnthein rnalzfla e and ca se. i to ab 'a aiustia: s de walls fz the; roov wh ch s pe n nsul r tolthea is o the as plus.

-5. The method of making; almetalliccartridge ase. whi h; compr s s app in an ax a y. rected, fo ce. t a;pylindfiealskere t l ns n end of the sleeve, said upset forming an internal lan e.- nartly fi lingca. r ve. a. b se.;p s; in re istr ic nih r with and a s f rm ng an... exter ali' periph tal id e l outside. oi; aid in rn a nd-th ap l n ress e n axial direction along 1 said ridge in V a direction; toward the; upse nda fithesleeve to exert a, eammin a on. rcin .t intern l. flan e. deep y; n said groove andturninet eflanee a a nst va sid allpithesr pve..

case ompri i a ocatin a b a i ment w t in end-woof a cylindrical sleeve over said brazing element; until .said .endof the sleeve. overlies a Deinh ral; groove in saidbase. plu upsett n sa d end of the sleevei to, form. an. internal flange entering said groove, applying a force directed inwardlyof saidgroove: to carry said flangedeeply.; into said-.-gro.ene, and l heating; the. cartridge case to cause the brazing element. to; melt and flow about. the:.-juncti0n of the cylindrical shell and, the. base plug; to ibraze them. together.

' JOHN nniussrrr. 

